Date of Award

Spring 5-1-2003

Document Type

Thesis

Degree Name

Master of Arts (MA)

Department

Life Sciences

First Advisor

George S. Bakken

Second Advisor

Michael J. Angilletta

Third Advisor

Steven L. Lima

Abstract

Temperature regulation in birds has been studied for several decades. However, most studies have been limited to the thermal effects of air. This is surprising considering the abundance of waterfowl and the significant amount of time that many birds spend immersed in water. While we do know that water has a thermal conductivity that is 23 times that of air, the effect of water temperature on temperature regulation remains unknown. Though the thermal effect of water seemingly has a strong influence on the thermoregulation of birds, neonatal aquatic birds seem particularly susceptible. Many aquatic neonates, such as mallard ducklings, enter the water within days posthatching, yet most neonatal chicks delay entry into the water for several months and even up to a year. This delayed entry has been largely attributed to the fact that chicks hatch with down feathers which repel water very poorly compared to the adult contour feathers that they will eventually molt into. Furthermore, neonatal chicks that enter the water so soon post-hatching are incapable of producing uropygial oil which has been suggested to aid in repelling water. Uropygial oil comes from the uropygial gland which is not functional until 7- 10 days post-hatching. This oil has been hypothesized to aid in retaining a layer of air in the plumage of birds which keeps birds separated from the water minimizing heat loss by conduction to the water. It was our intention to test whether uropygial oil aids in thermoregulation of swimming chicks and quantify the amount of heat loss that water inflicts upon neonatal chicks. Since body temperature (T b) would be such an important parameter to this study, we were also interested in developing a non-intrusive method to measure body temperature with the use of a radiometric infrared camera. Current methods for measuring temperatures in birds involve surgery or encumbering wires which can result in inaccurate measurements ofT b. IV We examined the importance ofuropygial oil, the use of an infrared thermal camera to estimate body temperature, and attempted to quantify the thermoregulatory effects of both air and water temperature on 3-4d old mallard ducklings (Anas platyrhynchos). Ducklings were initially tested with a variety of oil treatments, including uropygial oil, and a control to test for the importance. In a second experiment, the scalp temperature of swimming ducklings was measured and compared to thermocouple temperatures and we used these to create a body temperature model. Finally, 0 2 consumption was recorded on swimming ducklings exposed to air temperatures {Ta) from 10 to 45°C and water temperatures {Tw) from 5 to 30°C to examine the thermal effects of both air and water that swimming birds are exposed to in natural conditions.

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